Filtering attachment for anesthetizing machines



Dec. 8, 1931. HElDBRlNK 1,835,157

FILTERING ATTACHMENT FOR ANJESTHETIZING MACHINES Filed Oct. 25, 1928 2 Sheets-Sheet l m I a Inveni'or: w- Jy/(Hezdbn'nk /7 i' torn gs.

1931- J. A. HEIDBRINK 1,335,157

FILTERING ATTACHMENT FOR ANZESTHETIZING MACHINES Filed Oct. 25, 1928 2 Sheets-Sheet 2 I Jqg (Heic/bn'nk. By M i'i'brneya I n ven tor.-

Patented Dec. 8, 1931 l "J'AYFAQ HEIDBRI'NK, or MINNEAPOLIS; MmnEsoTA FTLTERTNG ATTACHMENT Ton ANZESTHETIZVING nnonmns Application filed October 25- w. Serial naemese.

My invention relates to filtering attachments forianaesthetizingmachines for the purpose of" filtering from" the gas exhaled by the patient, impurities such as carbon diox- L idthrown oflfl withthe exhaled gas as waste products of body metabolism; The gasthus purified may be breathed over again by. the patient and repeatedly purified and again breathed in. Since anaestheticgases are expensive, economy in the use thereof is desirable. In the manner above stated, two or three gallons of gas such as nitrous oxid which is unchanged by its excursion'through the body,may be usedto produce anaesthesia for- 1 an hour or more. It is common'practice among anaesthetists, even with a filter not 1n use, to supply the patient w1th less volume of gas than 1s sufficient to'suppl'y breathing so that there will be some rebreathingof ex-v 26 haled gas containing carbon dioxid, the object being to stimulate respiration with the carbon dioxid thus retained, itbeing well known that carbon dioxidis a respiratory stimulant. In filtering devices now commonly used, all the exhaled gas must pass through the filter and substantially all of the carbon dioxid is removed so that'there is practically no rebreiathing of carbon dioxid. An object of ,my invention is to provide a device that will function in connection with rebreathing for removing a predetermined amount of carbon dioxid from the .gas exhaled by the patient before the gas/is again inhaled. It is well known as above stated that in administering gaseous anaesthetics, it is usually desirable to supply some carbon dioxid to the patient in order to stimulate respiration. Since carbon dioxid is expelled from the lungs of the patient, rebreathing as common y employed provides a means for furnishing the patient. with carbon dioxid.

It is'found however that under difi'e'rent conditions, and for difierent' patients, it isexthe amount of carbon dioxid which 1s supplied and sometimes it mayeven be advisable to remove the carbon dioxid as fast'as it is expelled from the lungs before the gas is rebreathed. I" have, therefore, devise the at tachment herein disclosed embodying afilter tremely desirable to beable to readily vary.

forthe carbon dioxid which may be quickly set for removing amounts of carbon dioxid from the exhaled gas varying from zero up to substantially complete removal. Many anaesthetists introduce carbon dioxid in definite amounts run from's'eparate tanks to the reservoir or breathing bag of the aneesthetiz er hereinafter called theanaesthetizer bag for stimulating the patientis respiration.

ihere'fore another object of my invention is to be able to admitcarbon dioxidto said a naesthetizer bag and have this carbon dioxid pass from this bag to the patient without cominginto contact with the purifying material which would absorb the carbon dioxid. Another object of my invention is to provide means forquickly changing from purifying gas as above described to suppl'yin the patient with a continuous volume of fresh gas from the anaesthetizer and vice versa.

' The full objects and advantages ofjmy invention will appear in connection with the detailed description thereof, and the novel features of my inventive idea will be particu larly pointed out in the claims. v y g In thelaccompanying drawings which illustrate apractical embodiment of my. invention, Fig. 1 is a top plan view of theattachment. Fig. 2 is a sectional elevational view on an enlarged scale taken on the line 2 2 of Fig. 1.. Fig. 3 is a view in section onthe line 3-.3. of Fig. 2 on the same scale 7 as Fig. 1. "Fig. 4 is a view corresponding in a generalwayitoFig. 3bnt showingsome of the partsoperated intoa diiferentposition. Fig. 5 is a view' in cross-section on the line 55 of Fig. 2. Fig. '6 is a- View in cross section on thefline 66of Fig. 2. Fig. 7 is a view in cross section on theline,7 7 of Fig." 2.

'Mygdeviceincludes' a casing L 10, one'en d of which is connected by atube' 12 with any suitable form of anaesthetizing rhachine adapted to mixed-gases for-anaesthetizing purposes. As shown, the casing 10 is-made intwo parts helditogether on the inside by 9 a threaded ring 13." The casing 10 has'a tubular extension 14 to which an inhaler 16 is attached. A'conical member18 is secured to the end of the casinglq opposite the end to which the tube 12'is attached. The outer end of the conical member 18 carries an internally threaded annular flange 20 to which one end of a cylinder 22 is secured, this end holding a screen 24 in place as shown in Fig. 3. Secured to the outer end of the cylinder 22 there is a conical member 26 terminating in a cylindrical portion 28 to which an auxiliary rebreathing bag 30 is attached, this bag being hereinafter referred to as the filter bag. A screen 32 is held in place at the outer end of the cylinder 22, this screen having a disklike deflector 33 secured to its central portion. The space between the two screens is filled with filtering material which will absorb carbon dioxid, the impurity in exhaled anaesthetic gases. ,A material suitable for this purpose consists of what is commonly known as soda-lime, which is in medium sized crystals. This material is indicated by letter F in Fig. 3. The side of the casing 10 is provided with an adjustable exhaling valve 34 of well known construction. The conical member 18 is provided with an internalgroove for receiving a ring or gasket 36 which constitutes a seat for a plunger valve 38-secured vto the forward end of a rod 40 which extends slidably through a spiderlike support 4-2 carried by the casing 10. A coiled spring i4: interposed between the support 42 and an enlargement 46 on the rod 40 tends to hold the valve 38 in closed position as shown in Fig. 3. The enlargement i6 is engaged by a cam 48 secured to the inner end of a shaft 50 rotatably held in a packing gland 52 secured to the casing 10. an operating handle 54 issecured to the outer end of the shaft 50 which also carries a pointer 56 for the purpose of indicating the extent of opening and closing of the valve 38. The rear portion of the rod 40 extends slidably through a spiderlike support 58 carried by the forward end of a sleeVe'GO slidably supported in the ring 13. As best shown in Fig. 2, the outside of the sleeve 60 carries a ring valve 62 adapted to cooperate with a valve seat 64 formed on the rear of the ring 13. An enlargement 66 secured to the rod 40 engages the member 58 carried by the sleeve 60 when the valve 38 is 'in closed position as shown in Fig. 3 and this engagement moves the sleeve rearwardly so that the ring valve 62 ismoved oii' its seat. It should be noted that there is a' space between the ring valve 62 and the inside of the casing and that the sleeve contains perforations 68 ahead of the ring 62 so that when the partsare in the position of F ig. 3, the filter is .closed off and free passage is allowed in both directions between the inhaler and the anaesthetizing machine. The gas exhaled by the patient cannot now pass through the filtering material F to the filter bag 30. In this manner, the anaesthetizer functions :in all respects as though the filter was not attached. It is during this use that the exhaling valve 34- functions to permit the escape of exhaled gases. Also when any fresh gases are being supplied from the anaesthetizer while the filter is functioning, the exhaling valve 34 is set so as to cause this valve to remain closed until the filter bag becomes filled or distended to the desired extent. A coiled spring 70 surrounds the rod 40, being interposed between the member 58 and an enlargement 72 secured to the rear end of the rod. lVhen the cam 48 is moved from thegposition of Fig. 3, into the position of Fig. 4, the valve 38 is opened and the sleeve60 is moved forwardly so as to close the valve which is constituted by the ring 62. The spring 70 holds the sleeve 60 forwardly resiliently at this time so that the valve .62 is closed .even in case it should become worn. The enlargement 72 on the rear endof'the rod lOcarries radially extending fingers 74 while the :rear end of the sleeve 60 carries an inwardly {PTO- jecting ring 76. Asfiap per valve 78 is placed in the sleeve 60 between the ring .76 and the fingers 74. This valve is in the form of a disk having a number of spaces located .between radial projections 80 whose ends have free sliding engagement with the inside .of the sleeve 60. \Vhen the patient inhales with the cam 48 in the position shown in Figs. 2 and 4-, gas passes to the inhaler from the bag 30 and may also pass to the inhaler from the ,anzesthetizer since the valve 78 is sucked into the position shown in Fig. 1 so that gas can pass through the spaces located between the projections .80. However, when the patient exhales, the valve .78 is forced back against the ring .76 as shown in Fig. 2 so that all of the exhaled gas passesithrough the filtering material F to the bagSO, it .being noted that the spaces between the projections 80 do not extend inwardly ,as far as the inner margin of the ring 7G.so that the .valve is closed when moved into this position.

The operation and advantages of my invention will be readily understood iniconnection with the foregoing description. When the device is set in the position shown in Fig. with the valve .38 closed, :there is no filtering of the exhaled gas and the anaesthetizer functions as though its tubing wereconnected directly .to an inhaler shaving the vusual exhaling valve. When the deviceis set in the position shown in Figs. 2 and 4, the patient inhales from the bag 30 gas which has passed twice through the filtering material F and he can also inhale some gas :directly from the anaesthetizer past the flapper valve 78 but none past the valve .62. The'flapper valve .78 is of light construction and opens readily at thebeginning of the inhalation to admit from the anaesthetizing bag since this valve opens with less resistance than the resistance offered by the filtering material to the passage of gastherethrough. When .the anaesthetizer bag is exhausted, the remainder of the inhalation is taken from the filter bag 30. In this manner, any'fresh gas such as carbon dioxid coming from the anaesthetizer reaches the patient without passing through the filtering material which absorbs carbon dioxid. Since it requires some time to collect carbon dioxid from the patients breathing, it is considered by some anaesthetists that it is preferable to supply carbon dioxid from a tank more quickly and in more definite amounts than can be done by relying upon rebreathing. When the patient exhales with the device in the position shown in Figs. 2

and 4, the exhaled gas passes out through the filtering material to the bag 30, the-flapper valve 7 8 closing as shown in Fig. '2 and preventing any of the exhaled gas from passing back to the anaesthetizing machine, the valve 1 62 remaining closed. It will be understood that the device provides for removing amounts of carbon dioxid from the exhaled gas varying from zero up to substantially complete removal, since when the valve 38 is being opened, the valve ring 68 is being correspondingly closed and vice Versa. The proportion of the exhaled gas which is subjected to the action of the filtering material is indicated by the position of the pointer 56. My filtering attachment may be used with any suitable anaesthetizing. machine such as shown for instance in reissuePatent No. 15,- 874 to Jay A. Heidbrink dated July 22, 1924:.

I claim:

1. A filtering attachment for anaesthetizing machines comprising a casing, an inhaler connected to said casing only, a filter at one end connected to said casing, a filter bag connected to the other end of said filter only, a valve controlling only the passage between said cas ing and said filter, a connection for connecting said casing with the anaesthetizing machine, a valve controlling the passage between said connection and said casing, and means for operating said valves to open one of them in the ratio by which the other is closed and vice versa. 3

2. A filtering attachment for aneesthetizing machines comprising a ca sing, an inhaler connected to said casing only, a filter connected at one end to said casing, a filter bag connected to the other end of said filter only, a valve controlling only the passage between said casing and said filter, a connection for connecting said casing with the anaesthetizing machine, a valve controlling the passage between said connection'and said casing, means for operating said valves to open one of them in the ratio by which the other is closed and vice versa, and a valve for said machine connection operating independently of said second valve adapted to be opened by suction produced by inhalation and closed by pressure produced by exhalation.

3. A filtering attachment for anaesthetizing machines comprising a casing, an inhaler connected to said casing only, a filter connected at one end to said caslng, a filter bag connected to the other end of said filter only, a plunger valve controlling the passage between said casing and said filter, a connection for connecting said casing with the anaesthetizing machine, a sliding sleeve interiorly spaced within said casing, a ring valve secured around said sleeve, said sleeve having perforations in advance of said ring valve, a ro to which said plunger valve and said sleeve are attached, a cam for controlling the position of said rod whereby one of said valves is opened in the ratio by which the other is closed and vice versa, and a valve for said machine connection operating independently of said ring valve adapted to be opened by suction produced by inhalation and closed by pressure produced by exhalation.

4. A filtering attachment for anaesthetizing machines comprising a'casing, an inhaler connected to said casing only, a filter connected at one end to said casing, a filter bag connected to the other end ofsaid filter only, a plunger valve controlling the passage between said casing and said filter, a connection for connecting said casing with the anaesthetizing duced by inhalation and closed by pressure produced by exhalation.

In testimony whereof I hereunto afiix my signature.

- JAY A. HEIDBRINK. 

